Low Levels Of Microorganisms Research Articles

In situ antimicrobial behavior of materials with copper-based additives in a hospital environment

Copper and its alloys are effective antimicrobial surface materials in the laboratory and in clinical trials. Copper has been used in the healthcare setting to reduce environmental contamination, and thus prevent healthcare-associated infections, complementing traditional protocols. The addition of copper nanoparticles to polymer/plastic matrices can also produce antimicrobial materials, as confirmed under laboratory conditions. However, there is a lack of studies validating the antimicrobial effects of these nanocomposite materials in clinical trials. To satisfy this issue, plastic waiting room chairs with embedded metal copper nanoparticles, and metal hospital IV pools coated with an organic paint with nanostructured zeolite/copper particles were produced and tested in a hospital environment. These prototypes were sampled once weekly for 10 weeks and the viable microorganisms were analysed and compared with the copper–free materials. In the waiting rooms, chairs with copper reduced by around 73% the total viable microorganisms present, showing activity regardless of the microorganism tested.Although there were only low levels of microorganisms in the IV pools installed in operating rooms because of rigorous hygiene protocols, samples with copper presented lower total viable microorganisms than unfilled materials. Some results did not have statistical significance because of the low load of microorganisms; however, during at least three weeks the IV pools with copper had reduced levels of microorganisms by a statistically significant 50%. These findings show for the first time the feasibility of utilizing the antimicrobial property of copper by adding nanosized fillers to other materials in a hospital environment.

Impact of Controlling Bacteria in Feed on Broiler Performance During a Clostridial Challenge.

Three studies were conducted using Clostridium perfringens as an intestinal challenge to produce necrotic enteritis (NE). The studies consisted of two battery screening studies and one production study in floor pens. The purpose of the trials was to determine if reducing the level of microorganisms in feed consumed by broilers reduced the impact of a nonfeed-based Clostridial challenge. In all studies, C. perfringens challenged broilers consuming feed containing lower levels of microorganisms compared to control feed exhibited significantly ( P < 0.05) better feed conversion (feed conversion was improved by 14% in battery trials and by 4.2% in the pen trial) than did C. perfringens-challenged broilers consuming control feed. In battery trials, body weight gain and NE-associated mortality were also significantly improved in C. perfringens-challenged broilers consuming feed containing lower levels of microorganisms (16.5% improvement in body weight gain and 72.5% reduction in NE-associated mortality). In the pen trial, body weight gain and NE-associated mortality appeared unaffected by feed microbial quality. No effect was observed on lesion scores. The present data indicate that reducing the level of microorganisms in feed can ameliorate some of the performance losses associated with a Clostridia challenge.

A Pseudo-Outbreak of Pseudomonas putida and Stenotrophomonas maltophilia in a Bronchoscopy Unit

Background: Endoscopes represent the medical devices most commonly linked to health care-associated outbreaks and pseudo-outbreaks. Most of the recent outbreaks and pseudo-outbreaks have resulted from contaminated automated endoscope reprocessors (AER) or the use of damaged or malfunctioning bronchoscopes or contaminated equipment. Objectives: We investigated a pseudo-outbreak of Pseudomonas putida and Stenotrophomonas maltophilia recovered from bronchial washing (BW) specimens obtained during bronchoscopy in a bronchoscopy unit. Methods: Samples were obtained from environmental surfaces in the endoscopy suite, bronchoscopes, and bronchoscopic dispensable material, and specimens of cleaning solutions, cleaning brushes, the AER, and the ultrasound system were sent for bacterial culture. Medical records were reviewed to identify possible infections after a bronchoscopy. Results:P. putida and S. maltophilia were isolated from BW samples of 39 patients. The bronchoscopy models Olympus BF-1T160 and BF-160 were contaminated. Both bronchoscopes and other contaminated material (cleaning brushes, diluted cleaning solutions, and the sink) were isolated, but new cases continued to appear. The AER was recently installed, and new connections were used for the water lines and new tubes were connected to the AER. Initially, specimens were obtained from the external circuits and the internal walls of the AER. Finally, cultures were made from the filters on the water lines, and growth of P. putida and S. maltophilia was found. The investigation revealed that the BW specimens were contaminated because sterile saline was injected by means of the biopsy port of the bronchoscope and was recovered through the same channel by means of the proximal suction port. No patients developed clinical signs or symptoms of infection, but the positive cultures did lead to treatment of 21 patients. Conclusions: We described a pseudo-outbreak related to a contaminated bronchoscope because of inadequate installation of the AER for used new water lines and because the new tubes were connected to the AER. The antibacterial filters of the AER used tap water, and this may have contained low levels of microorganisms. No serious clinical complications derived from this pseudo-outbreak.

Evaluation of Prerequisite Programs Implementation and Hygiene Practices at Social Food Services through Audits and Microbiological Surveillance

Prerequisite programs are considered the most efficient tool for a successful implementation of self-control systems to ensure food safety. The main objective of this study was to evaluate the implementation of these programs in 15 catering services located in Navarra and the Basque Country (regions in northern Spain), through on-site audits and microbiological analyses. The implementation of the prerequisite program was incomplete in 60% of the sample. The unobserved temperature control during both the storage and preparation of meals in 20% of the kitchens reveals misunderstanding in the importance of checking these critical control points. A high level of food safety and hygiene (absence of pathogens) was observed in the analyzed meals, while 27.8% of the tested surfaces exceeded the established limit for total mesophilic aerobic microorganisms (≤100 CFU/25 cm²). The group of hand-contact surfaces (oven door handles and aprons) showed the highest level of total mesophilic aerobic microorganisms and Enterobacteriaceae, and the differences observed with respect to the food-contact surfaces (work and distribution utensils) were statistically significant (P < 0.001). With regard to the food workers' hands, lower levels of microorganisms were observed in the handlers wearing gloves (that is, for Staphylococcus spp we identified 43 CFU/cm2 on average compared with 4 CFU/cm2 (P < 0.001) for those not wearing and wearing gloves, respectively). For a proper implementation of the prerequisites, it is necessary to focus on attaining a higher level of supervision of activities and better hygiene training for the food handlers, through specific activities such as informal meetings and theoretical-practical sessions adapted to the characteristics of each establishment.

The microbiological profile of Jamaican Ackees (Blighia sapida)

PurposeThe aim of this paper is to study the microbiological profile of the ackee fruit during maturation.Design/methodology/approachAckees at ripening stage five, mature but unopened, were allowed to ripen naturally on the trees or on ripening racks used in commercial processing. The microbiological profile of fruits from this stage to that where they had ripened to the point just prior to decay (stage ten) were assessed. Aerobic and anaerobic mesophilic and thermophilic sporeformers and vegetative cells, total coliforms, E. coli, lactic acid bacteria, yeasts and molds at each stage were determined using standard methods.FindingsThe number of microorganisms on the tree‐ripened fruits was higher than those ripened on racks. Mesophilic aerobic and anaerobic spore‐forming organisms were present in greater numbers than thermophiles at all stages of maturity. Coliforms, excluding E. coli, were found on the tree‐ripened ackees particularly in the latter stages of ripening. Lactic acid bacteria and yeasts and molds found on both tree and rack‐ripened fruit may be the predominant agents in the microbiological spoilage of ackees during ripening.Originality/valueThis study is the first to assess the microbiological profile of ackees during ripening. It indicated that the relatively low levels of microorganisms of economic or public health significance during both tree‐ and rack‐ripening processes would not affect the commercial sterility of the canned product, even with a moderate thermal process (Fo of 3). It also suggests that controlled rack‐ripening of ackee fruit during commercial processing could improve the microbial quality of the processed product.

Multidisciplinary approach of the hyperarid desert of Pampas de La Joya in southern Peru as a new Mars-like soil analog

The distribution of living organisms, organic matter, and chemical properties in Mars-like environments on Earth can be used as a model to guide the investigation of possible habitable environments on Mars. This work aims to demonstrate that the place known informally as the “Mar de Cuarzo” (Sea of Quartz) in the Pampas de La Joya desert southern Peru (between 16°S and 17°S latitude), contains soils with characteristics similar to those found on the Martian surface. Using a multidisciplinary approach, we studied the environmental data, geology, organic matter content, oxidant activity, and microbiology of this area. Our data show that (1) Mar de Cuarzo is a hyper arid area with a lower concentration of organic matter than those found in the Mars-like soils from Yungay area (Atacama Desert in Chile), while at the same time having, comparable extreme environmental conditions, and very low levels of microorganisms. (2) The detrital components of the soils come essentially from the Andean volcanic chain and local outcrops of Precambrian gneisses and Cretaceous granitic batholiths. (3) The presence of microclimates, geomorphological features, and the high influence of the “El Niño Southern Oscillation (ENSO)” allowed the formation of exotic and heterogeneous chemical deposits in these soils, including iron oxides, sulfates, and other evaporites. (4) Thermal volatilization in these soils (using methods similar to the Viking and Phoenix instruments) shows high oxidant activity. (5) Labeled release experiment (similar to the Viking instrument) shows high degradation of nutrients added in these soils. Altogether, the Mar de Cuarzo area in the Pampas de La Joya is an interesting place for astrobiological studies as a new analog to Mars, and for comparative analyses with other hyperarid analogs as Yungay.

Airway Inflammation in Paper Mill Workers

Paper mill workers are exposed to culturable microorganisms (MOs). We hypothesized that inflammatory airway response could be detected in sputum of nonsymptomatic workers. From four paper mills, we included 29 healthy nonsmoking men. Workers exposed to high levels of MOs (HMOE, n = 17) were compared with workers exposed to low levels of MO (LMOE, n = 12). A reference group of 22 healthy, nonsmoking, nonexposed (NE) men were also included. We performed differential cell counts of induced sputum, studied gene expressions of isolated sputum macrophages and analyzed inflammatory parameters, including matrix metalloproteinases. Sputum from HMOE workers had a significantly higher percentage of neutrophils than that from LMOE workers (P < 0.05) and NE controls (P < 0.001). There was also an increased gene expression of different pro-inflammatory cytokines, interleukin-6, tumor necrosis factor-alpha, and macrophage inflammatory protein-1beta in isolated airway macrophages and increased levels of total matrix metalloprotease-9 activity in induced sputum from the HMOE group. Our findings indicate that paper industry workers exposed to MOs develop subclinical airway inflammation.

Is a 24-h cyclic closed enteral feeding system microbiologically safe in geriatric patients?

Background and aims: The microbiological quality of a 1-l closed enteral feeding system (CS) was prospectively monitored under clinical conditions simulating cyclic feeding over a 24-h period in geriatric patients.Method: The set was connected after diet sampling (T0). After 5-h feeding, the set was disconnected and a sample taken (T5). Diet was sampled after 12 h before (T12A) and after a 10 ml diet-flush of the set (T12B), after 24-h (T24) and in the pouch (P24). Concentrations of micro-organisms were considered significant when above 104 colony-forming units per millilitre.Results: Twenty-one CS were examined. T0 samples were all sterile; 10 out of 21 T5 were contaminated. The microbiological content of the diet was lower in T12B, compared to T12A (P=0.002). None of the P24 samples was contaminated; 19 were sterile and two contained low levels of micro-organisms that had been previously found in the sets.Conclusion: The CS was sterile before connecting to the patient. Retrograde contamination of the set was observed without contamination of the pouch after 24-h hanging time. Performing a diet-flush decreased the rate of diet contamination at the distal extremity of the set. Thus, cyclic enteral nutrition using the same pouch during a 24-h period seems to be safe in geriatric patients.

Control of milk processing based on rapid detection of micro-organisms

To monitor critical control points (CCPs) in the food industry, mainly parameters that can be measured by physical–chemical techniques are applied. In this study, various microbiological methods were used to monitor the development of micro-organisms during thermisation and pasteurisation of milk. The results show that of the methods currently available both the Bactoscan analysis and the ATP method offer possibilities for application as an `emergency brake'. The main problem is the sensitivity of the techniques. Levels of 10 4–10 5 micro-organisms per ml can be measured, but this is not sufficient to adjust a production process. Techniques based on particle size (distribution), spectroscopy and impedance were not able to differentiate between milk samples containing low levels of micro-organisms and highly contaminated milk. In addition, detection of metabolites produced by micro-organisms offers no alternative; high concentrations of bacteria are already present at the moment any signal can be measured. Therefore, more research is necessary before successful implementation of in-process applications can be guaranteed.